1. Field of the Invention
The present invention relates to an articulating fence post for a fencing or gating system and, more particularly, to a radially articulating fence post and gating system.
2. Description of the Related Art
Farmers and ranchers use fences, walls, hedgerows and other boundary markers to demarcate territory, and to control ingress and egress of persons and animals from and to the territory boundaries. With the advent of large cattle and sheep ranches, particularly in the Western United States, fences are used primarily to restrain domestic livestock from leaving a fenced-in or enclosed area. These fences are typically built from four or five horizontally spaced strands of barbed wire, or smooth wire mounted on wooden fence posts that are driven into the ground. A single fence, often stretching for miles, is used to delineate a xe2x80x9crangexe2x80x9d or xe2x80x9cpasturexe2x80x9d where herds of cattle, or other grazing animals, are confined.
In recent years, the use of fencing to delineate multi-purpose land utilization has become more prevalent in all regions of the country making ingress and egress from these restricted areas more of a concern. In all areas of the country, multi-purpose land use methods have brought crop cultivation and the raising of livestock together on the same land. These multi-use methods involve dividing a tract of land into several parcels and rotating the function of the parcels between crop cultivation and livestock feeding. These methods typically involve concentrating dense populations of livestock, such as feeder cattle and dairy cattle, on one parcel while crops, such as grains and seeds, are being cultivated on the others. Since cattle fed in this manner are in high density, barbed wire fences, and fences that have electrified strands of wire, are needed to confine the cattle in the parcel. Multi-purpose land use methods have gained widespread acceptance in the agriculture business because they generate increased yields of table meat from cattle by providing abundant food supplies for fattening cattle prior to slaughter.
With the requirement for increased agriculture production, especially in arid climates, sophisticated irrigation systems and methods have become a necessity to increase acreage yields. Today, these systems are usually automated, using computers, and can cover extended acreage without being manned. Water pressure and electricity are commonly used to provide the energy to move these systems. The irrigation systems have mechanized means of movement such as drive wheels mounted under spray irrigation carriages. A pivotal irrigation system, for example, is anchored at a center point and rotates about that point on large cleated wheels, mounted under a spray irrigation carriage, to sweep out an irrigation circle, which can be a mile or more in diameter.
The close proximity of cattle pastures and domestic crops created by modern, multi-purpose land use methods have put an unforeseen burden on irrigation systems. Typical stationary fence posts, necessary for separating cattle pastures from growing crops, greatly hinder the mobility of irrigation systems over a tract of multi purpose farmland. Large irrigation systems designed to efficiently irrigate large tracts of land, such as pivotal irrigation systems, become impractical if stationary fence posts obstruct them.
One approach, which allows a fenced area to be irrigated, has been to place gaps in the fence, which are wide enough for the cleated wheels of the irrigation system to pass. Unfortunately, the cleated wheels are so wide that the gaps in the fence are large enough to let livestock, including cattle, pass as well.
Another approach is to have crews move the fence in the path of the irrigation system and then replace it. This is labor intensive and expensive. It would therefore be advantageous to have fence posts that could articulate under the force of the moving irrigation system wheels, yet be resilient enough to retain livestock. Unfortunately, there are a number of problems associated with such a system. First, the fence posts must be able to yield to the force of the cleated wheels and articulate from its upright position, perpendicular to the ground, to a substantially flattened position that is parallel with the ground. Second, the fence system must maintain the strand integrity to keep from snapping wire strands as the fence articulates.
There are additional problems with prior art fence post systems. Those that have some kind of resilient means, such as a spring mechanism, which allow the fence posts to spring back to an upright position after being knocked down by the irrigation system, are hinged at their base so as only to pivot in a single plane. If an irrigation system does not approach the fence post from a direction that is perfectly aligned with the articulation direction of the fence post system, then the irrigation system imparts side loads on the fence posts and can cause permanent damage to both the fence post and irrigation systems. This problem is particularly acute for the widely used irrigation systems that rotate around a fixed center point. These systems commonly exert side load forces on the fence posts, causing either the posts or the wire strand to break or to be damaged.
Additionally, with large expanses of fencing, used primarily to restrain domestic livestock, ingress and egress is cumbersome, requiring a passer to open or close a conventional gate. Western style fences of barbed wire, or smooth wire mounted on wooden fence posts which often stretch for miles, require remote gates to allow ranchers or farmers access to the fenced area. When irrigation is required on part of the pasture the need for more frequent access points increases.
Presently, there is a need for an articulating fence post for fencing systems as well as and gating systems to facilitate passage of the irrigation system and accommodate the side loads exerted on the fence by the irrigation system. This need is especially great for fence post and gating systems which have delicate strands of electrified fencing wire which are easily snapped under the strain of an impinging irrigation system that moves along an arc that is not perpendicular to the fence line. In addition large expanses of fence posts, whether articulating or not, require gates which allows ease of ingress and egress. It would be advantageous to have a fence post for a fencing system and a gating system, which would collapse and then right itself upon passage of a vehicle or the like without damage to the fence line or the post.
It has now been discovered that the problems encountered with prior art gating for stationary and articulating fencing systems can be overcome by the present invention. In the broad aspect of the present invention, the fence post is a resilient, isotropically articulating member, which supports or facilitates gating systems for both stationary and articulating fencing systems. In accordance with the present invention, the fence posts resiliently yield to forces exerted in substantially all directions, including directions other than those perpendicular to the fence line.
In accordance with the broad aspect of the present invention, an isotropic fence post resiliently yields to an object (e.g., a mobile irrigation system or a ranch vehicle) approaching the fence post from any direction, even a direction substantially parallel to a fence line, as defined by the fence posts. The articulating fence post yields to objects resistively. For example, the fence post will resiliently yield to a mobile irrigation system, or in the case of an articulated gating segment, to a ranch vehicle, but not to the force of a cow moving against the fence or the gate. The resistance to a force pressing against the articulating fence or gateposts is variably set, causing the posts to substantially yield only when a preset amount of force is applied. For example, the resistance can be set such that the force of a strong wind or cows will not cause the posts to articulate, but the force of an impinging irrigation system or a ranch vehicle will cause the posts to articulate.
The gating system of the present invention has at least one articulating post and preferably three posts, including at least one resiliently articulating center post that is aligned between a pair of end posts, wherein a fencing material is strung between adjoining posts. The at least one center fence post of the present invention is a resilient, isotropically articulating member that preferably includes a shaft adapted for affixing flexible fencing material; a resilient, isotropically flexible member having a top end for rigid communication with the shaft and a bottom end for rigid communication with a base element; and an anchor element, permanently and immovably connected to the base element, for anchoring the base. The fencing material preferably comprises strands of wire, either single strand or braided, including strands of electrically conducting material for electric fences, and strands of barbed wire.
In accordance with the invention, the articulating posts can be used as fence posts or gate posts. For example, the end fence post elements of the system of the instant invention can be resiliently articulating, or they can be rigid, non-articulating supports. In one embodiment, the end fence and/or gate posts are non-articulating. It will be realized that in accordance with the invention the end post elements may also form the apex of a corner that is formed from two linear segments of fence, which are joined together at an angle (i.e., the end fence post is a corner post). At least one segment so joined can be radially articulating.
In accordance with the present invention, the resilient, isotropically articulating fence posts have an isotropically flexible member for allowing a shaft to resiliently articulate between a position substantially perpendicular to the ground, and a position substantially parallel to the ground. In a preferred embodiment, the isotropically articulating member is a spring, and preferably a coil spring, that is capable of radial, resilient articulation. In another embodiment, the isotropically flexible member is a segment of flexible hose, preferably made from plastic or rubber.
A fence material tensioning means, such as a coil spring, is used to attach a strand of fencing material to at least one post element of the gating system. The tensioning means provides flexibility to assure the integrity of the fence material when the fence is under stress. This is to further assure that strands of fencing material in the gating system will not break when the gateposts are articulated.
In one embodiment, the tensioning means includes at least one spring element connected at one end to a strand of fencing material and on the other to a variable set tensioning means, such as a turnbuckle, which adjusts the amount of tension on the strand. In another embodiment, the tensioning means comprises two spring segments having a variable set tensioning means there between. In another embodiment, the tensioning means comprises a spring-loaded pulley assembly rotatably attached to a post, which can be stationary or articulating depending upon the use. In accordance with this embodiment a strand of fencing material is spooled on the pulley and held in tensioned engagement therewith.